Adapting to a Hotter Earth

I’m going to quote the beginning, and hope that lures you into reading the rest. This is important stuff!

Adapting to climate change

Facing the consequences

Global action is not going to stop climate change. The world needs to look harder at how to live with it.

ON NOVEMBER 29th representatives of countries from around the world will gather in Cancún, Mexico, for the first high-level climate talks since those in Copenhagen last December. The organisers hope the meeting in Mexico, unlike the one in Denmark, will be unshowy but solid, leading to decisions about finance, forestry and technology transfer that will leave the world better placed to do something about global warming. Incremental progress is possible, but continued deadlock is likelier. What is out of reach, as at Copenhagen, is agreement on a plausible programme for keeping climate change in check.

The world warmed by about 0.7°C in the 20th century. Every year in this century has been warmer than all but one in the last (1998, since you ask). If carbon-dioxide levels were magically to stabilise where they are now (almost 390 parts per million, 40% more than before the industrial revolution) the world would probably warm by a further half a degree or so as the ocean, which is slow to change its temperature, caught up. But CO2 levels continue to rise. Despite 20 years of climate negotiation, the world is still on an emissions trajectory that fits pretty easily into the “business as usual” scenarios drawn up by the Intergovernmental Panel on Climate Change (IPCC).

The Copenhagen accord, a non-binding document which was the best that could be salvaged from the summit, talks of trying to keep the world less than 2°C warmer than in pre-industrial times—a level that is rather arbitrarily seen as the threshold for danger. Many countries have, in signing the accord, promised actions that will or should reduce carbon emissions. In the World Energy Outlook, recently published by the International Energy Agency, an assessment of these promises forms the basis of a “new policies scenario” for the next 25 years (see chart 1). According to the IEA, the scenario puts the world on course to warm by 3.5°C by 2100. For comparison, the difference in global mean temperature between the pre-industrial age and the ice ages was about 6°C.

The IEA also looked at what it might take to hit a two-degree target; the answer, says the agency’s chief economist, Fatih Birol, is “too good to be believed”. Every signatory of the Copenhagen accord would have to hit the top of its range of commitments. That would provide a worldwide rate of decarbonisation (reduction in carbon emitted per unit of GDP) twice as large in the decade to come as in the one just past: 2.8% a year, not 1.4%. Mr Birol notes that the highest annual rate on record is 2.5%, in the wake of the first oil shock.

But for the two-degree scenario 2.8% is just the beginning; from 2020 to 2035 the rate of decarbonisation needs to double again, to 5.5%. Though they are unwilling to say it in public, the sheer improbability of such success has led many climate scientists, campaigners and policymakers to conclude that, in the words of Bob Watson, once the head of the IPCC and now the chief scientist at Britain’s Department for Environment, Food and Rural Affairs, “Two degrees is a wishful dream.”

The fight to limit global warming to easily tolerated levels is thus over. Analysts who have long worked on adaptation to climate change—finding ways to live with scarcer water, higher peak temperatures, higher sea levels and weather patterns at odds with those under which today’s settled patterns of farming developed—are starting to see their day in the uncomfortably hot sun. That such measures cannot protect everyone from all harm that climate change may bring does not mean that they should be ignored. On the contrary, they are sorely needed.

Related

This entry was posted on Thursday, December 23rd, 2010 at 1:23 am and is filed under climate. You can follow any responses to this entry through the RSS 2.0 feed.
You can leave a response, or trackback from your own site.

Post navigation

16 Responses to Adapting to a Hotter Earth

Interesting article. It seems odd to me that every single change in climate is assumed to be bad. Tens of thousands currently die prematurely due to cold winter events, and the models used to say that the biggest impact of greenhouse warming would be in the winter rather than the summer.

In the US, the latest Census data show movement toward the south and west, that is, hotter and drier places. (An important confounding factor is that those states also tend to have lower taxes, less unionization, lower regulation, and higher economic growth.) I also haven’t heard about land prices on higher ground gaining relative to those on lower ground. So on both current and future-oriented behavior, do we have strong evidence that hotter is a lot worse?

One interesting point in the article is that the models are all over the map on regional impacts and are unlikely to get any better. So the “richer is better” and “growth is good” prescriptions are the best general precaution we can take to deal with what might be on the way. That conclusion has an impact on mitigation policies, which unambiguously make us poorer by making fossil energy more expensive. Partial or ineffective mitigation efforts may be the worst of both worlds.

It seems odd to me that every single change in climate is assumed to be bad.

I’m sure some people assume that, but not the Economist article I’m citing! It writes:

Arctic summer sea ice goes, allowing more shipping and mining…

and

Tropical cyclones, which account for much of the damage the sea does to the land, may become less frequent.

and

In northern climes some land will become more suitable for farming as springs come sooner…

All of these good sides come along with “buts”, which one can see by reading the article. So, please — nobody suggest that I’m sugarcoating the truth here! But this article, and all the serious studies on global warming that I’ve seen, do not assume, or even conclude, that every single change is bad.

Up to 2 degrees of global warming, studies suggest that crop yield gains and adaptation, especially at high latitudes, could balance losses in tropical and other regions. Beyond 2 degrees, studies suggest a rise in food prices.

There is of course a certain tendency for us, and living organisms in general, to optimize our behavior to the conditions at hand. The result is that any change in average temperature either up or down will cause disruptions, which will be negligible if the change is sufficiently slow, but greater if the change happens faster.

And this — I believe — is the main problem with global warming, rather than any intrinsic “hot = bad” effect. An ice age would also be very disruptive! But that doesn’t seem likely in the next few thousand years: right now, the issue is that we are raising CO2 concentrations at a truly dramatic rate, taking us out of the regime characterized by glacial cycles:

It is good to imagine the extrapolation of this graph to the 900 ppm figure you mentioned earlier.

So the “richer is better” and “growth is good” prescriptions are the best general precaution we can take to deal with what might be on the way.

In the current scheme of things, where economic growth is highly correlated to increased energy usage and thence to increased CO2 output, “growth is good” assumes “more CO2 isn’t so bad”. But I disagree with this, for lots of reasons, discussed all over this blog and not worth repeating now.

There may be other people here interested in discussing with you whether “growth is good” — and that would be an extremely enlightening debate to have, provided that people put forth facts and clear arguments, rather than nastiness.

I’ll give you the Arctic shipping point, but the article did, as you said, attach “buts” to every other positive and did not attach “buts” to the negatives. For example, the CO2 fertilization effect was mentioned in grudging fashion, but its impact on making plants more water-efficient was not. The article did not even discuss the advantages of warmer winters in terms of lives saved and dislocation reduced. It was still interesting and useful in that Economist way of laying out a whole bunch of details readably in one place.

My point about US migration patterns is that within sample there isn’t a lot of evidence that people like it colder. These migratory movements subject people to much greater than 2 degree temperature increases. If US agricultural productivity increases and US winters become milder and more people get to live in climates more like the ones that people are already moving toward, then the US is not going to be ravaged too much by the projected warming. (Not saying other countries don’t matter, but I don’t know enough about India and Africa to judge the claims about harm to them.)

Perhaps my perspective is warped by living in Los Angeles. We know, with a high degree of probability, that the whole place is eventually going to be severely damaged by a major earthquake. That seems like a much bigger risk than sea-level rise or increases in drought and yet we are not really well set up for resilience after it happens. Most of these adaptation issues–whether for earthquakes or sea-level rise–are more individual, corporate, city, and state matters than national or international ones because most of the impacts are localized.

My point about US migration patterns is that within sample there isn’t a lot of evidence that people like it colder. These migratory movements subject people to much greater than 2 degree temperature increases. If US agricultural productivity increases and US winters become milder and more people get to live in climates more like the ones that people are already moving toward, then the US is not going to be ravaged too much by the projected warming. (Not saying other countries don’t matter, but I don’t know enough about India and Africa to judge the claims about harm to them.)

If global warming simply meant that every day were 2 °C warmer (3.6 °F for folks in the US) than it would have been, it probably wouldn’t matter a lot to most people.

Even sea level rise would have limited impact in most parts of the United States. It matters a lot more in Bangladesh, where according to the UNEP, 1.5 meters in sea level rise would displace 18 million people:

Worldwide, the National Academy of Sciences estimates that a mere 0.6 meter sea level rise would displace 3 million people and raise the risk of flood for millions more. They expect at least this amount of sea level rise by 2010, due to thermal expansion and loss of ice from glaciers and small ice caps.

This estimate doesn’t count the big unknown factor: Greenland and the West Antarctic Ice Sheet. If all the ice in Greenland were to melt, it would cause an additional sea level rise of 7.2 meters. If all the ice in the West Antarctic Ice Sheet were to melt, it would cause a further rise of 4.8 meters. Of course we don’t expect these to completely melt in the next century — but they’re melting faster than people expected when the last IPCC report was written, so there’s a lot of uncertainty here. I haven’t seen any good guesses.

In the short term, say 20 years or so, I think the main economic damage from global warming will come from weather-related disasters. It’s not the 2 °C average temperature rise that’s the problem: it’s the rise in extreme weather events!

All these seem to be part of a trend toward increased weather variability, which is what I’d expect from a hotter, more energetic atmosphere and ocean. Munich Re, one of the world’s largest reinsurers, wrote in September 2010:

Floods in central Europe, wildfires in Russia, widespread flooding in Pakistan. The number and scale of weather-related natural catastrophe losses in the first nine months of 2010 was exceptionally high…. Munich Re emphasises the probability of a link between the increasing number of weather extremes and climate change.

Globally, 2010 has been the warmest year since records began over 130 years ago, the ten warmest during that period all falling within the last 12 years. The warmer atmosphere and higher sea temperatures are having significant effects. Prof. Peter Höppe, Head of Munich Re’s Geo Risks Research/Corporate Climate Centre: “It’s as if the weather machine had changed up a gear. Unless binding carbon reduction targets stay on the agenda, future generations will bear the consequences.”

Munich Re recorded a total of 725 weather-related natural hazard events with significant losses from January to September 2010, the second-highest figure recorded for the first nine months of the year since 1980. Some 21,000 people lost their lives, 1,760 in Pakistan alone, up to one-fifth of which was flooded for several weeks. Overall losses due to weather-related natural catastrophes from January to September came to more than US$ 65bn and insured losses to US$ 18bn. Despite producing 13 named storms, the hurricane season has been relatively benign to date, the hurricanes having pursued favourable courses.

Munich Re’s natural catastrophe database, the most comprehensive of its kind in the world, shows a marked increase in the number of weather-related events. For instance, globally there has been a more than threefold increase in loss-related floods since 1980 and more than double the number of windstorm natural catastrophes, with particularly heavy losses as a result of Atlantic hurricanes.

The rise in natural catastrophe losses is primarily due to socio-economic factors. In many countries, populations are rising, and more and more people moving into exposed areas. At the same time, greater prosperity is leading to higher property values. Nevertheless, it would seem that the only plausible explanation for the rise in weather-related catastrophes is climate change. The view that weather extremes are more frequent and intense due to global warming coincides with the current state of scientific knowledge as set out in the Fourth IPCC Assessment Report.

There are at present insufficient data on many weather risks and regions to permit statistically backed assertions regarding the link with climate change. However, there is evidence that, as a result of warming, events associated with severe windstorms, such as thunderstorms, hail and cloudbursts, have become more frequent in parts of the USA, southwest Germany and other regions. The number of very severe tropical cyclones is also increasing. One direct result of warming is an increase in heatwaves such as that experienced in Russia this summer. There are also indications of a higher incidence of atmospheric conditions causing air mass formation on the north side of the Alps and low-lying mountain ranges, a phenomenon which can result in floods. Heavy rain and flash floods are affecting not only people living close to rivers but also those who live well away from traditionally flood-prone areas. Although climate change can no longer be halted, even with the help of very ambitious schemes, it can still be curbed.

People sometime blame the increasing economic loss due to disasters on socioeconomic factors, and you’ll see from the above that this is largely true. However, there’s good evidence that weather-related losses are on the rise due to changing climate. Dr. Peter Hoeppe, head of the Geo Risks Research Department at Munich Re, wrote:

For me the most convincing piece of evidence that global warming has been contributing already to more and more intense weather related natural catastrophes is the fact that while we find a steep increase in the number of loss relevant weather events (about tripling in the last 30 years) we only find a slight increase in geophysical (earthquake, volcano, tsunami) events, which should not be affected by global warming. If the whole trend we find in weather related disaster should be caused by reporting bias, or socio-demographic or economic developments we would expect to find it similarly for the geophysical events.

On the other hand, there will probably be some benefits to global warming. For example, there may be a boom in the Arctic as circumpolar shipping routes open up and ice and permafrost retreat. There’s an interesting blog devoted to this topic:

If all the ice in Greenland were to melt, it would cause an additional sea level rise of 7.2 meters. If all the ice in the West Antarctic Ice Sheet were to melt, it would cause a further rise of 4.8 meters. Of course we don’t expect these to completely melt in the next century — but they’re melting faster than people expected when the last IPCC report was written, so there’s a lot of uncertainty here. I haven’t seen any good guesses.

Actually there’s some information on the Azimuth Project sea level rise page. It looks like the current range of estimates point to 0.6-2 meters of sea level rise by 2010. So, we could easily see about 10-18 million people in Bangladesh needing to move to higher ground.

First, The Copenhagen Diagnosis, written in 2009, was intended to serve as an interim evaluation of the evolving science before the 5th IPCC report, which is not due for completion until 2013. Its executive summary says, among other things:

• Current sea-level rise underestimates: Satellites show great global average sea-level rise (3.4 mm/yr over the past 15 years) to be 80% above past IPCC predictions. This acceleration in sea-level rise is consistent with a doubling in contribution from melting of glaciers, ice caps and the Greenland and West- Antarctic ice-sheets.

• Sea-level prediction revised: By 2100, global sea-level is likely to rise at least twice as much as projected by Working Group 1 of the IPCC AR4, for unmitigated emissions it may well exceed 1 meter. The upper limit has been estimated as 2 meters sea-level rise by 2100. Sea-level will continue to rise for centuries after global temperature have been stabilized and several meters of sea level rise must be expected over the next few centuries.

Second, this is a paper which aims to estimate the sea level rise with a greater variety of factors included in the analysis than is generally done:

The authors say their estimates are in line with past sea level responses to temperature change, and they suggest that estimates based on ice and ocean thermal responses alone may be misleading. With six different IPCC radiative forcing scenarios they estimate a sea level rise of 0.6–1.6 m, and are confident the rise will be between 0.59 m and 1.8 m.

I agree that “growth is good” or if you prefer a lesser evil, at least as long as Earth population keeps growing. If economic growth won’t follow population growth the average living conditions will have to deteriorate.

srp, may you live in interesting times. Change isn’t necessarily good or bad in toto, but can require much more extra work for it to be at least as good for adapted people as no change. For instance, sea level rise can require work to move or replace existing docks that otherwise would have been fine for more decades. It’s hard to see economically how that extra work isn’t bad, and hard to see why any “buts” would make any difference to it.

Speaking of migrating, I was working the other day in 16 degrees C contaminated discharge in -13 C air. Individuals of migratory (as well as hibernating) species that normally wouldn’t have been there then, including thousands of waterfowl, abounded in the artificial spring. Within just a few years, the local population of overwinterers is an order of magnitude higher than migratory individuals of the same species. Good? Bad?

There’s still the small detail that all the most positive scenarios still assume the economy continues to use exponentially growing amounts of energy.

As someone else here pointed out, there is no other affordable energy to feed growth on earth but fossil fuel. Every tech fix for ever doubling use of the earth runs into troubles unseen anyway,… just like all the unseen trouble we’re now running into, for jinxing our lives with using “do that until trouble stops us” as being our plan.

Really, don’t we need to be sensible for once??? The essay is also partly about very clearly understanding the problem of living in a physical world and using ideological thinking as your map.

Munich Re says: “The rise in natural catastrophe losses is primarily due to socio-economic factors. In many countries, populations are rising, and more and more people moving into exposed areas. At the same time, greater prosperity is leading to higher property values. Nevertheless, it would seem that the only plausible explanation for the rise in weather-related catastrophes is climate change. The view that weather extremes are more frequent and intense due to global warming coincides with the current state of scientific knowledge as set out in the Fourth IPCC Assessment Report.”

Pielke Jr. has worked on this a lot, as have others. Most conclude that in the US, at least, all the increases in payouts are due to socioeconomic factors.

(Note that the economic interests of Munich Re are heavily tilted to getting us to mitigate CO2, on the off-chance that that reduces their payouts. Insurance firms are equally biased in favor of expensive auto-safety features that may not provide net benefit to consumers.)

Munich Re further argues: “For me the most convincing piece of evidence that global warming has been contributing already to more and more intense weather related natural catastrophes is the fact that while we find a steep increase in the number of loss relevant weather events (about tripling in the last 30 years> we only find a slight increase in geophysical (earthquake, volcano, tsunami) events, which should not be affected by global warming. If the whole trend we find in weather related disaster should be caused by reporting bias, or socio-demographic or economic developments we would expect to find it similarly for the geophysical events.”

This argument is incorrect. Economic development has led to people moving to desirable areas, like coastlines, not to volcanos or earthquake zones. And since earthquake events follow a power law, we may well be seeing a “black swan” effect where The Big One in California will swamp all other disaster costs in one shot.

Finally, I’m surprised you didn’t respond to my two points that 1) we have other disaster scenarios to invest against that are likely much more serious (e.g. earthquakes) and 2) most of the adaptive responses should take place at a sub-national level. CO2 mitigation naturally works best at a supranational level, adaptation at a sub-national one. Instead we have California attempting CO2 mitigation and the national government encouraging people to live in flood-prone areas through subsidized insurance. Wacky.

As usual, it was more fun to talk about areas of disagreement. But they’re good points.

You’re right that people are more drawn to seashores than earthquake-prone regions, and this needs to be taken into account.

I consider Pielke Jr. to be an intelligent man with a bit of an axe to grind. I thought that Munich Re, being in the business of insurance, would know a thing or two about the risks we face. But since it also has interests at stake here, as you point out, that means I can’t trust them either. This is typical of the puzzles I’m trying to solve these days: we can’t always trust “experts”, we have to do real work to sort out the data, and we have to constantly be on guard against getting locked into an ideology that filters all the data we receive, giving us preconceived results. “Both sides” in the climate change debate — though surely there are more than two — are extremely susceptible to this ideological filtering. I often feel it happening in myself: it’s extremely attractive to feel I know what’s going on. But, to really find out what’s going on, I need to resist this pull.

I take it back, I have finally won today, which basically means that i got to the year 2120 with less than 3 degrees increment without destroying civilization. I mean, Latin America has to be rebuilt and there’s war raging in China, but other than that, it’s an excellent result :-)

Anyway, i am not sure how accurate are the underlying climate and economics models (this is the successor of the BBC climate challenge game), but they seem to have at least a decent level of detail (and it is really fun to play).

I mean, Latin America has to be rebuilt and there’s war raging in China, but other than that, it’s an excellent result :-)

It sounds like a fun game, and it sounds like you did spend a lot of time playing it, against your own advice.

I’m very glad you’re helping Tim figure out the right amount of noise per time-step for that stochastic differential equation. I would join in, but I only have limited access to the computer in the hotel lobby here in Hue!

Vietnam is a fascinating place. They’ve been attacked many times: most recently by the Americans, and before that by the French, but more often by the Chinese. So, everything old is damaged or destroyed. But they kept fighting back, so they’re still here, and now they are struggling very hard to advance themselves economically. There’s a lot of pollution, a lot of motorbikes driving all over the place, and a lot of poor people, but also a lot of energy. The United States seems like a very sleepy place, in comparison.

Yes, i did spend some time playing, that game was a little addictive, to me at least.

I’m very glad to be of help. In any case those are the kind of simulations i can build and run in about 5 minutes, so it’s no problem, and besides, it’s fun.

I’m glad you are enjoying Vietnam, sounds fascinating. The part of Italy where I am from (http://en.wikipedia.org/wiki/Apulia) also has a long story of being invaded by everyone and their sisters, but we didn’t really bother to fight back, except in a few cases.

How To Write Math Here:

You need the word 'latex' right after the first dollar sign, and it needs a space after it. Double dollar signs don't work, and other limitations apply, some described here. You can't preview comments here, but I'm happy to fix errors.